UA CoolSwitch brief uses an exclusive coating on the inside that pulls heat away from your skin, so you actually feel cooler. Grid-textured micro-mesh fabric is both tough & breathable. UPF 30+ protects your skin from the sun's harmful rays. Material wicks sweat & dries really fast. Anti-odor technology prevents the growth of odor-causing microbes. Reflective logos for greater visibility on low-light runs.